Third-Party Vendor Risk Assessment Playbook

December 17, 20234 min read

Playbook Objectives:

  • Evaluate the current state of the organization’s third-party vendor risk management processes.
  • Enhance the detection and response capabilities of the organization against potential third-party vendor-related breaches.
  • Improve interdepartmental coordination and communication during third-party vendor security incidents.
  • Train the incident response team on handling real-life attack scenarios originating from third-party vendors.
  • Identify and remediate security gaps concerning third-party vendor connections to our network.
  • Improve contractual agreements and security expectations with third-party vendors.

Difficulty Level:

  • Intermediate to Advanced. Participants should have a foundational understanding of network security, incident response, and third-party risk management processes.


  • Company Name: FinSecure Bank
  • Attack Scenario: A midsize financial services company, FinSecure Bank, relies heavily on a network of third-party vendors to provide essential services ranging from cloud hosting to customer support. Despite a robust internal security policy, recent industry breaches have prompted the bank to scrutinize the risk that third-party vendors pose to its operations and customer data.
  • The breach scenario centers on a cybercriminal group, “ShadowByte”, exploiting vulnerabilities in a software provided by one of FinSecure’s primary vendors, “PayFlow Solutions”. PayFlow’s software is integrated with the bank’s transaction processing system. The attackers managed to leverage a remote code execution vulnerability due to PayFlow’s insufficient patch management practices, allowing ShadowByte to gain access to FinSecure Bank’s internal network.
  • The bank’s Chief Information Security Officer (CISO), Laura Sintek, along with her security team, including IT specialist Marcus Lee and network analyst Jasmine Fell, need to identify how the breach occurred, assess the extent of the damage, contain the threat, and secure their network against further attacks. This exercise will test their ability to respond to a real-world incident involving third-party risk.


  • Incident Response and Third-Party Risk Management

Exercise Attack Steps:

  • Reconnaissance: Analysts will assess the information accessible from PayFlow Solutions, identifying potential vulnerabilities in their interaction with FinSecure Bank.
  • Initial Compromise: White-hat attackers simulate finding a vulnerability in PayFlow’s software and exploit it to gain unauthorized access to the bank’s network.
  • Establish Foothold: Once inside the network, the exercise attackers deploy tools to maintain their presence and establish backdoors while avoiding detection.
  • Privilege Escalation: Attackers escalate their privileges to obtain administrative access, simulating the critical breach point.
  • Lateral Movement: The exercise includes simulated lateral movement within FinSecure Bank’s network, reaching sensitive internal systems to illustrate the impact a third-party breach can have.
  • Data Exfiltration: Attackers package sensitive data, preparing it for extraction to highlight potential data loss.
  • Discovery and Analysis: FinSecure Bank’s incident response team is tasked with identifying the breach using security tools and network analysis.
  • Containment: The team must act swiftly to contain the compromised systems and prevent further unauthorized access.
  • Eradication: Following containment, the team identifies and removes all malicious software and backdoors left by the attackers.
  • Recovery: The team works on restoring systems to normal operation securely and analyses for any residual risks.
  • Post-Incident Assessment: After the simulation, a thorough review identifies any shortcomings in the response, lessons learned, and potential improvements to the third-party vendor risk management processes.
  • Exercise Review and Report: Participants and stakeholders convene to discuss the outcomes, review the response effectiveness, and create an action plan for mitigating future third-party risks.